Deflectable interstitial ablation device

ABSTRACT

A deflectable interstitial ablation device includes an elongated housing, an electrode mounted within the elongated housing, a driver coupled to the electrode, an imaging device integrally mounted within the elongated housing and a deflection system disposed within the elongated housing. The elongated housing has a proximal end, a distal end, and a deflectable segment. The electrode is deployable from a first position within the elongated housing to a second position a predetermined distance beyond the distal end of the elongated housing. The electrode further has a flexible portion capable of deflecting with the deflectable segment of the elongated housing, and can be deployed by the driver with a sufficient force such that penetration of the urethral wall occurs in a single motion. The imaging device further has a flexible portion capable of deflecting with the deflectable segment of the elongated housing. The deflection system has a proximal end in communication with a steering mechanism, for controllably deflecting the deflectable segment of the elongated housing by any angle. The deflection of the deflectable segment allows deflection of the electrode and the imaging device, thus facilitating proper placement of the electrode.

FIELD OF THE INVENTION

[0001] The invention relates to an interstitial ablation device andmethod for performing tissue ablation, and in particular, to an improvedinterstitial ablation device providing enhanced electrode placement andcontrol.

BACKGROUND

[0002] Ablation devices can be used to treat tumors in the body. Inparticular, ablation devices can be used to treat benign prostatichypertrophy or hyperplasia (BPH), a condition resulting in anenlargement of the prostate gland. This is a common medical problemtypically experienced by men over 50 years of age. Hyperplasticenlargement of the prostate gland often leads to compression of theurethra, which results in obstruction of the urinary tract.

[0003] An ablating needle can be used with a cystoscope to treat BPH byablating a prostatic adenoma, which is a benign tumor inside theprostate. To perform the ablation procedure, a physician inserts adistal end of the cystoscope into the urethra of a patient while viewingthe advance through an eye piece of the cystoscope. The needle electrodeis also introduced into the urethra through a working channel of thecystoscope. The cystoscope and the needle electrode are typicallyintroduced inside the urethra sequentially. The distal end of the needleelectrode is positioned adjacent the prostate near the prostaticadenoma. The physician then causes the needle electrode to penetrate theurethral wall, such that it is positioned inside the prostatic adenoma.Radiofrequency (RF) energy is applied to the needle electrode tocoagulate tissue surrounding the electrode. Coagulation causes necrosisof the prostatic adenoma, resulting in atrophy of the prostate and areduction in the compressive forces that interfere with urine flowthrough the urethra.

[0004] During the ablation procedure, it is important that the needleelectrode be positioned precisely, because inaccurate electrodeplacement can cause incontinence in the patient. Visualization istypically provided by inserting the needle electrode through acystoscope. One disadvantage of the ablation device insertable through acystoscope is that it is difficult to feed the device through a workingchannel of the cystoscope and requires a lot of juggling which can makeaccurate placement of the needle electrode difficult. Moreover, it isoften difficult to observe the distal tip of the needle electrode as theelectrode penetrates the urethral wall, because the distal end of theelectrode is typically deflected in order to penetrate the urethral wallwhile the viewing device itself does not deflect along with the needleelectrode.

[0005] Existing interstitial ablation systems are also uncomfortable forthe patients and cumbersome for the physician performing the procedure.Most cystoscopes and ablation systems integrating imaging devices tendto be rigid and uncomfortable for patients when inserted through a bodylumen such as the urethra. The systems also have numerous knobs anddials that the physician must adjust for controlling needle deployment,fluid introduction, and application of RF energy.

[0006] Thus, there remains a need for an interstitial ablation devicethat provides accurate electrode placement and better control of theelectrode, reduces patient discomfort and simplifies the process ofperforming ablation.

SUMMARY OF THE INVENTION

[0007] In one aspect, the invention features a deflectable interstitialablation device. In one embodiment, the device includes an elongatedhousing, an electrode mounted within the elongated housing, a drivercoupled to the electrode, an imaging device integrally mounted withinthe elongated housing, and a deflection system disposed within theelongated housing. The elongated housing has a proximal end, a distalend, and a deflectable segment. The electrode is deployable from a firstposition within the elongated housing to a second position apredetermined distance beyond the distal end of the elongated housing,and has a flexible portion capable of deflecting with the deflectablesegment of the elongated housing. The driver exerts a force sufficientto drive the electrode from the first position to the second position ina single motion. The imaging device has a flexible portion capable ofdeflecting with the deflectable segment of the elongated housing. Thedeflection system controllably deflects the deflectable segment of theelongated housing to a desired angle. The deflection system has aproximal end in communication with a steering mechanism.

[0008] In one embodiment, the imaging device includes a plurality ofillumination optical fibers and a plurality of viewing optical fibersextending from the proximal end to the distal end of the elongatedhousing. The viewing optical fibers can comprise a fused bundle ofviewing optical fibers surrounded by illumination optical fibers,wherein the viewing optical fibers are in communication with a lensdisposed at the distal end of the elongated housing. In anotherembodiment, the electrode is a hollow needle electrode and an insulationsheath surrounds the needle electrode. The needle electrode and theinsulation sheath are individually and slidably mounted inside theelongated housing, such that the insulation sheath is capable ofcovering a proximal portion of the needle electrode which extends beyondthe distal end of the elongated housing. In still another embodiment,the driver coupled to the electrode can exert a force within the rangeof ¼ lb to 1 lb to drive the electrode from the first position to thesecond position in a single motion.

[0009] In another embodiment, the device includes an elongated housing,an electrode mounted within the elongated housing, an imaging deviceintegrally mounted with the elongated housing, a deflection systemdisposed within the elongated housing, and a foot pedal for deployingthe electrode.

[0010] In another aspect, the invention features a method for treatingtissue. A deflectable interstitial ablation device is inserted into abody lumen which provides access to the tissue to be treated. Thedeflectable interstitial ablation device includes an elongated housinghaving a deflectable segment, a deployable electrode mounted within theelongated housing, a driver coupled to the electrode for exerting aforce to drive the electrode, an imaging device integrally mounted withthe elongated housing, and a deflection system disposed within theelongated housing. The distal end of the elongated housing is positionednear the tissue. The deflectable segment of the elongated housing isdeflected toward the tissue, thereby deflecting the electrode and theimaging device toward the tissue along with the deflectable segment. Theelectrode is deployed to penetrate a wall of the lumen and to position adistal end of the electrode adjacent the tissue. Radio frequency energyis applied to the electrode in an amount and for a duration sufficientto ablate the tissue.

[0011] In one embodiment, an insulation sheath is deployed to cover aproximal portion of the deployed electrode to protect the wall of thelumen from directly contacting the needle electrode during thetreatment. In another embodiment, a balloon disposed on a body of theelongated housing of the deflectable interstitial ablation device isinflated to secure the position of the elongated housing inside thelumen. In yet another embodiment, a basket disposed on a body of theelongated housing of the deflectable interstitial ablation device isexpanded to secure a position. In still another embodiment, the distalend of the elongated housing is connected to an actuator incommunication with a foot pedal and the foot pedal is depressed todeploy the electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The invention is described with particularity in the appendedclaims. The above and further advantages of this invention may be betterunderstood by referring to the following description taken inconjunction with the accompanying drawings.

[0013]FIG. 1A shows a side view of a deflectable interstitial ablationdevice according to one embodiment of the invention.

[0014]FIG. 1B shows a portion of the deflectable insterstital ablationdevice having a basket for maintaining the placement of the device in abody lumen, according to one embodiment of the invention.

[0015]FIG. 2 illustrates a deflecting segment of the deflectableinterstitial ablation device of FIG. 1A.

[0016]FIG. 3 shows a cross sectional view of the deflectableinterstitial ablation device of FIG. 1A cut through lines 3′-3″.

[0017]FIG. 4 shows a cross sectional view of a distal end of thedeflectable interstitial ablation device of FIG. 1A cut through lines4′-4″.

[0018]FIG. 5A is a side view of a kinetically deployable needleelectrode according to one embodiment of the invention.

[0019]FIG. 5B is a cross sectional view of the kinetically deployableneedle electrode of FIG. 5A prior to deployment.

[0020]FIG. 5C is a cross sectional view of the kinetically deployableneedle electrode of FIG. 5A in a loaded position.

[0021]FIG. 5D is a cross sectional view of the kinetically deployableneedle electrode of FIG. 5A with the needle electrode deployed.

[0022]FIG. 5E is a cross sectional view of the kinetically deployableneedle electrode of FIG. 5A with the needle electrode and the insulationsheath deployed.

[0023]FIG. 6 shows a transurethral interstitial ablation systememploying a foot pedal according to one embodiment of the invention.

[0024]FIG. 7 shows an actuator for deploying a needle electrodeaccording to one embodiment of the invention.

DETAILED DESCRIPTION

[0025] Referring to FIGS. 1A and 4, a deflectable interstitial ablationdevice 10 includes an elongated housing 12, an electrode 14 extendingwithin the elongated housing 12, an imaging device 16 integrally mountedwith the elongated housing 12 and a deflection system 18 disposed withinthe elongated housing 12. The electrode 14 can comprise a needleelectrode having a sharpened tip, or an electrode having a blunt tip.The elongated housing 12 has a proximal end, a distal end and adeflectable segment 22 further as further shown in FIG. 2. The elongatedhousing 12 can be constructed to be flexible so that the housing 12 maybe inserted into the urethra without much discomfort. In one embodiment,the housing 12, can be, for example, a flexible multi-lumen catheter. Inanother embodiment, the housing 12, can be, for example, a substantiallyrigid, single lumen catheter having a deflectable segment 22. In onedetailed embodiment, the housing 12 can have a diameter from about 15 to16 French. It is to appreciated that the diameter of the housing 12 canvary depending on the intended use of the ablation device 10.

[0026] In order to provide accurate placement of the electrode 14 insidethe urethra, the present invention further provides means forstabilizing the position of the device 10 before deploying the electrode14. In one embodiment, the elongated housing 12 of the inventionincludes a balloon 24 for securing the position of the device 10 whilethe electrode 14 is deployed at the ablation site. The elongated housing12 includes a fluid port with a luer fitting 26 for introducing a fluidsuch as, for example, air or water for inflating the balloon 24. Thefluid enters the balloon 24 through an inflation sleeve further shown inFIG. 2 to inflate the balloon 24. Another advantage provided by theballoon 24 is that the balloon 24 can block the blood vessels on theurethral wall and slow down heat conduction provided by the bloodvessels. In one embodiment, the balloon 24 is compliant enough to fitinside the urethra. In one detailed embodiment, the balloon isconstructed of latex or silicone. The diameter of the inflated balloon,in one embodiment, can be about 30 French.

[0027] In another embodiment, as shown in FIG. 1B, the elongated housing12 can include a basket 25 to stabilize the device 10 position duringdeployment of the electrode 14. The basket 25 can comprise a wire meshattached to an outer surface of the housing 12 surrounding the electrode14, the imaging device 16 and the deflection system 18. The housing 12can further be surrounded by an elongated sheath or catheter 27 suchthat the wire mesh comprising the basket 25 remains retracted duringplacement of the device and expands into the basket 25 shown in FIG. 1Bto secure the position and placement of the electrode 14 after theelectrode 14 has been exposed.

[0028] As shown, the proximal end of the elongated body 12 is incommunication with a detachable eye piece coupler 28. A detachable eyepiece 30 is coupled to the eye piece coupler 28, and the physicianobserves insertion of the device 10 into the urethra and the electrode14 deployment by looking into the eye piece 30.

[0029] The proximal end of the elongated body 12 is also incommunication with a handle 32. The handle 32 includes a slide member 34for controlling deployment of the electrode 14. In one embodiment, thehandle 32 can include two slide members (not shown), one for controllingthe movement of the electrode 14 and the other for controlling themovement of the insulation sheath 40. In another embodiment, the slidemember 34 can control the movement of the electrode 14 and theinsulation sheath 40 secured to the electrode 14, to expose apredetermined amount of the electrode 14. As shown, the handle 32 alsoincludes an electrical connector 38 for coupling the proximal end of theelectrode 14 to a power source (not shown). In a preferred embodiment,the power source is an RF generator, however it is to be appreciatedthat other energy sources can be used, such as a microwave generator.The handle 32 further includes a luer port 36 for injecting fluid and anirrigation port 31 for removing fluid. In one embodiment, the fluid canbe a conductive fluid for improving ablation procedures. Conductivefluids, can include, for example, saline and lydocaine. The use of aconducting fluid prevents desiccation of tissue and prevents an increasein the impedance during the ablation procedure.

[0030] Referring to FIG. 2, the electrode 14 can be deployable from afirst position within the elongated housing 12 to a second positionbeyond the distal end of the elongated housing 12 as shown. In oneembodiment, the electrode 14 deploys to a predetermined distance beyondthe distal end of the elongated housing 12. It is to be appreciated thatthe distance the electrode 14 deploys can vary depending on the intendedapplication. As shown, the electrode 14 also has a flexible portion 40 awhich deflects along with the deflectable segment 22 of the elongatedhousing 12. In one detailed embodiment, the deflectable segment 22 islocated at the distal end of the elongated housing 12 and has adimension of from about 2.5 cm to about 4.5 cm measured from the distalend of the housing 12. It is to be appreciated that the length of thedeflectable segment 22 can fall outside of the above range, depending onthe intended application of the device 10. In one embodiment, thedimension and position of the flexible portion 40 a of the electrode 14corresponds to that of the deflectable segment 22 of the elongatedhousing 12. Referring to FIG. 2, illustrated in phantom in a deflectedposition, is the deflectable segment 22 and electrode's flexible portion40 a at the distal tip of the elongated housing 12.

[0031] Referring to FIGS. 2 and 3, the electrode 14 can be a needleelectrode surrounded by an insulation sheath 40. The needle electrode 14and the insulation sheath 40 are placed inside an electrode guide tube41 disposed inside the elongated housing 12. The insulation sheath 40,for example, may be constructed from an insulating polymer material suchas polyimide. In another embodiment, the needle electrode 14 can becoated with an insulator, such as Teflon or ceramic. The needleelectrode 14 and the insulation sheath 40 can be individually andslidably mounted inside the elongated housing 12, such that theinsulation sheath 40 is capable of covering a proximal portion of theneedle electrode 14 extending beyond the distal end of the elongatedhousing 12. By adjustably covering a proximal portion of the electrode14 with the insulation sheath 40, the physician can control the amountof electrode 14 that is exposed, and thus control the conductive regionand consequently, the size of the ablation area. This feature isimportant in transurethral interstitial ablation of prostate tissue,because urethral walls can be protected from being ablated during theprocedure. Alternatively, the insulation sheath 40 can be fixed to aproximal portion of the needle electrode 14 and the needle electrode 14can be slidably mounted inside the elongated housing 12. In anotherembodiment, as shown in FIG. 3, the electrode 14 can comprise a hollowelectrode 14 including a passageway 43. In one embodiment, the hollowelectrode 14 has an inner diameter of approximately 0.011 inches and anouter diameter of approximately 0.02 inches. The insulation sheath 40has an outer diameter of approximately 0.03 inches and an inner diameterof about 0.025 inches. The electrode guide tube 41 has an inner diameterof about 0.039 inches. It is to be appreciated that the above dimensionsare illustrative, and are not intended to be restrictive, as otherdimensions can be used depending in whole or in part, on the intendedapplication of the device.

[0032] Referring to FIGS. 3 and 4, the imaging device 16 disposed insidethe elongated housing 12 includes a illumination region 44 and a viewingregion 42. Both regions 42 and 44 can include a plurality of opticalfibers 46 extending from the proximal end to the distal end of theelongated housing 12. In the embodiment of FIGS. 3 and 4, theillumination region 44 includes a plurality of optical fibers 46 incommunication with a light source (not shown) at a proximal end. Theplurality of optical fibers 46 surrounds the viewing region 42. Theviewing region 42 can include a fused bundle of optical fibers 48 incommunication with an objective lens 50 at the distal end for focusingan image. An example of the objective lens 50 is a gradient index(GRIN-self) objective lens having a diameter of about 0.039 inches. Theillumination region 44 and the viewing region 42 may be arranged inother ways and may comprise optical components other than or in additionto those described above. In other embodiments, other imaging devicescan be used for viewing the area of tissue in question. In oneembodiment, the imaging device 16 is surrounded by an outer sheathcomprising a polymeric material 47. In another embodiment, the imagingdevice 16 is disposed inside the elongated housing 12 without an outersheath. In one detailed embodiment, the imaging device 16 has a viewingangle 13 of about 70 degrees, as shown in FIGS. 1 and 2. It is to beappreciated that the viewing angle 13 can be greater or less than 70degrees depending in whole or in part, on the intended application ofthe device. Referring to FIGS. 1 and 4, the deflection system 18controllably deflects the deflectable segment 22 by an angle of up to180 degrees in one direction and 180 degrees in the opposite directionwith respect to the longitudinal axis of the elongated housing 12. Inone embodiment, the deflection system 18 includes a flexible wire 54extending from the proximal end to the distal end of the elongatedhousing 12 and a flat spring 56 in communication with the flexible wire54 disposed at the distal end of the elongated housing 12. The proximalend of the flexible wire 54 is in communication with a steeringmechanism 52, shown in FIG. 1A as mounted on the handle 32. The steeringmechanism 52 can pull the flexible wire 54 and cause the flat spring 56to gradually deflect toward a direction to which the wire 54 is pulled.Details of the steering mechanism are described in U.S. Pat. No.5,273,535, which is incorporated herein by reference. In one detailedembodiment, the deflection system 18 has an outer diameter ofapproximately 0.02 inches. It is to be appreciated that the diameter ofthe deflection system 18 can vary depending in whole or in part, on theintended application of the device.

[0033] Referring to FIGS. 5A-5E, in another embodiment, the deflectableinterstitial ablation device 10 further includes a driver 75 located inthe handle 32 and coupled to the electrode 14 for kinetically deployingthe electrode 14. In this embodiment, the electrode 14 can be a needleelectrode having a sharpened tip. The driver 75 exerts a forcesufficient to deploy the electrode 14 from inside the elongated housing12 to a position beyond the distal end of the elongated housing 12 in asingle motion. In one embodiment, the force of deployment can range fromabout ¼ lb to about 1 lb. A force in this range is sufficient to causethe electrode 14 to penetrate the urethral wall in a single motion.Kinetic deployment which permits sudden and high speed deploymentfacilitates electrode penetration through the urethral wall, reducingpatient discomfort and improving the accuracy and control of needledeployment. In the present embodiment, such kinetic deployment isachieved by employing a driver 75 comprising a spring-operated actuatingmechanism.

[0034] Referring to FIG. 5A, the handle 32′ includes slots 60 and 61having levers 62 and 63, respectively, and a recess 64 having anactuator 66 on an outer surface of the handle 32′. Referring to FIG.'S5B to 5E, contained within the housing 32′ are slide members 68 and 69.The slide member 68 is connected to the insulation sheath 40, and theslide member 69 is connected to the electrode 14. The lever 62 isconnected to the slide member 68 and the lever 63 is connected to theslide member 69. Reduced proximal sections 70 and 71 of the slidemembers 68 and 69 are received within spring coils 72 and 73,respectively. The actuator 66 is operatively coupled to the slide member69. In this embodiment, the electrode 14 and the insulation sheath40-are sequentially propelled.

[0035] Referring to FIG. 5C, prior to inserting the elongated sheath 12inside the body, the device 10 is loaded by pulling the levers 62 and 63in the proximal direction. As the lever 62 is pulled in the proximaldirection, a projection 74 on the slide member 68 slides over andcatches the distal surface of a catch or stop 76, and as the lever 63 ispulled, a projection 78 of the slide member 69 catches on a stop 80.Once the elongated sheath 12 is properly placed inside the body and thedeflectable segment 22 is deflected by a desired angle, the needleelectrode 14 and the insulation sheath 40 are deployed by pulling theactuator 66 proximally and then down.

[0036] Referring to FIG. 5D, as the actuator 66 is pushed down, the stop76 moves allowing the slide member 69 to move distally until theprojection 78 is restrained by a stop 82. The needle electrode 14 ispropelled forward as the sliding member 69 is moved by the force fromthe coiled spring 73. Referring to FIG. 5E, as the slide member 69 movesforward, and just before the end of its distal movement as theprojection 78 reaches the stop 82, a trigger member 86 on the slidemember 69 contacts a release member 88. Movement of the release member88 causes the projection 74 to disengage from the stop 76, such that theslide member 68 is propelled forward by the force of the coiled spring73. As the slide member 68 propels forward, the insulation sheath 40propels beyond the distal end of the elongated housing 12 covering apre-determined portion of the needle electrode 14.

[0037] Referring to FIG. 5D, in one embodiment, only the needleelectrode 14 is propelled with a spring operated actuating mechanism,while the insulation sheath 40 is glided over the needle electrode 14.Once the needle electrode 14 has penetrated the urethral wall, glidingthe insulation sheath 40 over the needle electrode 14 can be easilyachieved without causing much discomfort to the patient.

[0038] In one embodiment, depth of needle electrode 14 penetration iscontrollable, such that different locations within the prostate can bereached by the needle electrode 14. In one detailed embodiment, thesteering mechanism 52 described above can provide depth control. Fordeeper penetration, the electrode 14 tip can be deflected closer to 90degrees, whereas for shallow penetration, the needle electrode 14 tipcan be deflected by a smaller angle, such as, for example, 45 degrees.In another detailed embodiment, depth of electrode 14 penetration isadjustable using a slide member on the handle 32, which controlsmovement of the needle electrode 14 relative to the elongated housing12. In this embodiment, maximum penetration depth may be fixed byplacing a stop inside the handle 32.

[0039] Referring to FIG. 6, in another embodiment, the electrode 14 canbe kinetically deployed using a foot pedal. As shown, the interstitialablation system 89 includes a foot pedal 90, a control and power sourcemodule 92, an actuator, a light source 98, the deflectable interstitialablation device 10, and a return electrode 91. The light source 98supplies light to the illumination region 44 of the imaging device 16,described above in FIG.'s 3 and 4. As shown in this embodiment, thereturn electrode 91 is placed on the patient 110. The foot pedal 90 iscoupled to the control and power source module via a cable 94, and thecontrol and power source module 92 is coupled to the actuator 96 via acable 99. In operation, a physician performing an ablation procedureproperly places the ablation device 10 inside the patient's body, thensteps on the foot pedal 90 to deploy electrode 14, leaving his or herhands free to perform other functions. Additional features such asapplication of fluid to a treatment site, application of energy to theelectrode 14, and the triggering temperature measurement means at thedistal end of the electrode 14 may also be activated using the pedal 90.In one embodiment, the interstitial ablation system 89 can includeseveral foot pedal actuators for performing each of these functions. Inanother embodiment, the interstitial ablation system 89 can include onlyone foot pedal used to activate multiple functions. In this embodiment,the control module 92 may be programmed to control the order of theperformance of each function.

[0040] Referring to FIG. 7, shown is the actuator 96 which controlselectrode deployment. In the present embodiment, the actuator 96 cancomprise a solenoid 100. As shown, the solenoid 100 is coupled to thecontrol and power module 92 at a proximal end via a cable 105, andcoupled to the proximal end of the electrode 14 at a distal end via aluer fitting 104. The actuator 100 is held within an actuator housing102, which is coupled to the luer fitting 104. The luer fitting 104 issized and shaped to attach to the proximal end of the elongated housing12 of the deflectable interstitial ablation device 10. Alternatively,the luer fitting 104 may be sized and shaped to attach to a workingchannel of a flexible cystoscope for those applications in whichcystoscopes are used. When the foot pedal 90 is depressed, current fromthe power source 92 is applied to the solenoid 100, which forces theelectrode 14 to deploy beyond the distal end of the elongated housing12. Other types of actuators such as a rotary motors and linear motors,as well as other electromechanical devices can be used to perform thesefunctions as well. It is to be appreciated that, a number of foot pedalsand actuators for activating a mechanical event can be interchangeablyused to actuate the electrode 14, or provide fluid delivery andtemperature sensing at the treatment site.

[0041] The deflectable interstitial ablation device 10 of the inventionprovides many other features typically performed in ablation procedures.As briefly described above, the deflectable interstitial ablation device10 can be coupled to a fluid source to permits delivery of fluid to thehousing 12 or to an internal bore (not shown) formed in the electrode 14such that fluid is dispensed near the treatment site for providingcooling or for enhancing ablation. In such an embodiment, the fluid, canbe for example, an electrolytic fluid which increases the ablation area,or a fluid that provides therapeutic effects. In another embodiment, theelongated housing 12 can include a separate passageway suitable forfluid delivery. In both embodiments, fluid can be introduced through theluer port 36 (FIG. 1A). In another embodiment, the solenoid can becoupled to a syringe for introducing fluid inside the elongated housing12. Application of current to the solenoid in this case would cause thesyringe to discharge the fluid held within a fluid source into theelongated housing 12.

[0042] In another embodiment, the deflectable interstitial ablationdevice 10 can include a temperature sensing system for measuring tissuetemperature during the ablation procedure. In one detailed embodiment,the temperature sensing system can include a thermocouple disposed nearthe distal end of the electrode 14, such as by being fixed at the distalend of the insulation sheath 40 that is fixed to the electrode 14. Instill another embodiment, the device 10 can include an impedancemonitoring system in communication with the proximal end of theelectrode 14. The impedance monitoring system can measure impedance nearthe distal end of the electrode 14. The interstitial ablation device canfurther employ a feedback system that uses the temperature and or theimpedance data to control the delivery of RF energy to the electrode 14.The control module 92 can, for example, include means for automaticallyadjusting the magnitude and duration of the ablation energy delivered tothe electrode in response to one or both of these parameters. Theinterstitial ablation system can also include a safety feature whichcuts off the delivery of energy when the temperature or the impedancevalue exceeds a threshold value.

[0043] The deflectable interstitial ablation device 10 of the presentinvention does not require the use of an endoscope and therefore can beentirely disposable. The disposable device can attach to reusable eyepiece and other equipment such as a light source, and a control andpower source module. In an alternative embodiment, the imaging system 16can be removed from the device 10 for subsequent reuse.

[0044] As shown and described, the present invention features animproved transurethral interstitial ablation apparatus and method forperforming transurethral ablation While the invention has beenparticularly shown and described with reference to specific preferredembodiments, it should be understood by those skilled in the art thatvarious changes in form and detail may be made therein without departingfrom the spirit and scope of the invention as defined by the appendedclaims.

What is claimed is:
 1. A deflectable interstitial ablation device,comprising: an elongated housing having a proximal end, a distal end,and a deflectable segment; an electrode mounted within the elongatedhousing and deployable from a first position within the elongatedhousing to a second position a predetermined distance beyond the distalend of the elongated housing, the electrode having a flexible portioncapable of deflecting with the deflectable segment of the elongatedhousing; a driver coupled to the electrode for exerting a forcesufficient to drive the electrode from the first position to the secondposition in a single motion; an imaging device integrally mounted withthe elongated housing, the imaging device having a flexible portioncapable of deflecting with the deflectable segment of the elongatedhousing; and a deflection system disposed within the elongated housingfor controllably deflecting the deflectable segment of the elongatedhousing by any angle, the deflection system having a proximal end incommunication with a steering mechanism.
 2. The deflectable interstitialablation device of claim 1, wherein the driver comprises aspring-operated actuating mechanism.
 3. The deflectable interstitialablation device of claim 1, wherein the imaging device comprises aplurality of optical fibers.
 4. The deflectable interstitial ablationdevice of claim 3, wherein the imaging device further comprises a lensin communication with the optical fibers disposed at the distal end ofthe elongated housing.
 5. The deflectable interstitial ablation deviceof claim 3, wherein the imaging device comprises a plurality ofillumination optical fibers and a plurality of viewing optical fibersextending from the proximal end to the distal end of the elongatedhousing.
 6. The deflectable interstitial ablation device of claim 5,wherein the viewing optical fibers comprise a fused bundle of opticalfibers surrounded by the illumination optical fibers, and wherein theviewing optical fibers are in communication with a lens disposed at thedistal end of the elongated housing substantially perpendicular to alongitudinal axis of the housing.
 7. The deflectable interstitialablation device of claim 1, wherein the electrode comprises a needleelectrode and an insulation sheath surrounding the needle electrode, theneedle electrode and the insulation sheath being individually andslidably mounted inside the elongated housing, such that the insulationsheath is capable of covering a proximal portion of the needle electrodeextending beyond the distal end of the elongated housing.
 8. Thedeflectable interstitial ablation device of claim 7, wherein the driverdrives the needle electrode from the first position to the secondposition in a single motion and the insulation sheath is glided over theneedle electrode.
 9. The deflectable interstitial ablation device ofclaim 1, further comprising a handle in communication with the proximalend of the elongated housing.
 10. The deflectable interstitial ablationdevice of claim 9, wherein the handle includes first and second slidemembers, the first slide member in communication with the needleelectrode to control the movement of the needle electrode relative tothe elongated housing, and the second slide member in communication withthe insulation sheath to control the movement of the insulation sheathrelative to the elongated housing and the needle electrode.
 11. Thedeflectable interstitial ablation device of claim 7, wherein the needleelectrode is hollow.
 12. The deflectable interstitial ablation device ofclaim 11, further comprising a fluid transport member coupled to thehollow electrode for delivering a fluid through the hollow electrode.13. The deflectable interstitial ablation device of claim 1, wherein theelongated housing includes a stabilization balloon disposed along a bodyof the elongated housing.
 14. The deflectable interstitial ablationdevice of claim 1, wherein a proximal end of the electrode is adaptedfor communication with an energy source.
 15. The deflectableinterstitial ablation device of claim 1, wherein a proximal end of theimaging device is adapted for communication with a detachable eye piece.16. The deflectable interstitial ablation device of claim 9, wherein thehandle further comprises: a detachable eye piece coupler for coupling aproximal end of the imaging device to the detachable eye piece, and anelectrical connector for coupling a proximal end of the electrode to aradio frequency generator.
 17. The deflectable interstitial ablationdevice of claim 1, wherein the deflectable segment is disposed at thedistal end of the elongated housing.
 18. The deflectable interstitialablation device of claim 1, wherein the deflection system includes aflexible wire extending from the proximal to the distal end of theelongated housing and a flat spring disposed at the distal end of theelongated housing, the flexible wire having a proximal end incommunication with the steering mechanism, which pulls the wire togradually deflect the deflectable segment of the elongated housing. 19.The deflectable interstitial ablation device of claim 17, wherein thedeflectable segment deflects at an angle between 0 degrees to 180degrees with respect to a longitudinal axis of the elongated housing.20. The deflectable interstitial ablation device of claim 1, furthercomprising a temperature sensing system disposed within the elongatedhousing for measuring a temperature of a tissue region being ablated.21. The deflectable interstitial ablation device of claim 20, whereinthe temperature sensing system comprises a thermocouple.
 22. Thedeflectable interstitial ablation device of claim 1, further comprisingan impedance monitor in communication with the proximal end of theelectrode for measuring an impedance.
 23. The deflectable interstitialablation device of claim 1, further comprising: a control system inelectrical communication with the proximal end of the electrode; and afoot pedal for remotely activating deployment of the electrode.
 24. Thedeflectable interstitial ablation device of claim 23, further comprisinga power source in communication with the control system and the footpedal.
 25. The deflectable interstitial ablation device of claim 24,wherein the foot pedal remotely activates delivery of energy from thepower source to the electrode.
 26. The deflectable interstitial ablationdevice of claim 23, wherein the foot pedal further activates delivery offluid from a fluid delivery device through the elongated housing. 27.The deflectable interstitial ablation device of claim 23, wherein thefoot pedal further activates a temperature sensor disposed near a distalend of the electrode.
 28. The deflectable interstitial ablation deviceof claim 23, further comprising a cable in communication with the footpedal and an actuator in communication with the cable.
 29. Thedeflectable interstitial ablation device of claim 28, wherein theactuator comprises a solenoid and the cable includes a pair ofconductors in communication with the solenoid.
 30. The deflectableinterstitial ablation device of claim 28, wherein the cable includesconductors in communication with the electrode, a fluid delivery device,and a temperature sensor.
 31. The deflectable interstitial ablationdevice of claim 28, wherein the actuator is disposed inside an actuatorhousing in communication with a luer fitting.
 32. The deflectableinterstitial ablation device of claim 31, wherein the luer fitting isshaped and sized to attach to the proximal end of the elongated housing.33. The deflectable interstitial ablation device of claim 1, wherein theelongated housing is adapted for insertion inside a urethra for ablatinga prostate tissue with the electrode.
 34. The deflectable interstitialablation device of claim 33, wherein the needle electrode is capable ofadvancing through a urethral wall for applying radio frequency energy toa prostate tissue.
 35. A deflectable interstitial ablation device,comprising: an elongated housing having a proximal end, a distal end,and a deflectable segment; an electrode mounted within the elongatedhousing and deployable from a first position within the elongatedhousing to a second position a predetermined distance beyond the distalend of the elongated housing, the electrode having a flexible portioncapable of deflecting with the deflectable segment of the elongatedhousing; an imaging device integrally mounted with the elongatedhousing, the imaging device having a flexible portion capable ofdeflecting with the deflectable segment of the elongated housing; adeflection system disposed within the elongated housing for controllablydeflecting the deflectable segment of the elongated housing by anyangle, the deflection system having a proximal end in communication witha steering mechanism; and a foot pedal for remotely activatingdeployment of the electrode.
 36. A deflectable interstitial ablationdevice, comprising: an elongated housing having a proximal end, a distalend, and a deflectable segment; an electrode mounted within theelongated housing and deployable from a first position within theelongated housing to a second position a predetermined distance beyondthe distal end of the elongated housing, the electrode having a flexibleportion capable of deflecting with the deflectable segment of theelongated housing; a driver coupled to the electrode for exerting aforce within the range of ¼ lb to 1 lb to drive the electrode from thefirst position to the second position in a single motion; an imagingdevice integrally mounted with the elongated housing, the imaging devicehaving a flexible portion capable of deflecting with the deflectablesegment of the elongated housing; and a deflection system disposedwithin the elongated housing for controllably deflecting the deflectablesegment of the elongated housing by any angle, the deflection systemhaving a proximal end in communication with a steering mechanism.
 37. Amethod for treating tissue, comprising the steps of: a) inserting adeflectable interstitial ablation device into a body lumen whichprovides access to the tissue, the deflectable interstitial ablationdevice comprising: an elongated housing having a proximal end, a distalend, and a deflectable segment, an electrode mounted within theelongated housing, a driver coupled to the electrode for exerting aforce to drive the electrode from a first position within the elongatedsheath to a second position a predetermined distance beyond the distalend of the elongated housing, an imaging device integrally mounted withthe elongated housing, and a deflection system disposed within theelongated housing for controllably deflecting the deflectable segment ofthe elongated housing by any angle; b) positioning the distal end of theelongated housing near the tissue; c) deflecting the deflectable segmentof the elongated housing toward the tissue, thereby deflecting theelectrode and the imaging device toward the tissue along with thedeflectable segment; d) deploying the electrode to penetrate a wall ofthe lumen and to position a distal end of the electrode adjacent thetissue; and e) applying a radio frequency energy to the electrode in anamount and for a duration sufficient to ablate the tissue.
 38. Themethod of claim 37, wherein steps a) through e) are performed underobservation through an eye piece attached to the imaging device of thedeflectable interstitial ablation device.
 39. The method of claim 37,wherein the electrode comprises a needle electrode.
 40. The method ofclaim 39, further comprising deploying an insulation sheath to cover aproximal portion of the deployed needle electrode to protect the wall ofthe lumen from directly contacting the needle electrode during thetreatment prior to applying the radio frequency energy.
 41. The methodof claim 37, wherein the tissue is prostate tissue and the lumen is aurethra.
 42. The method of claim 37, further comprising the step ofinflating a balloon disposed on a body of the elongated housing of thedeflectable interstitial ablation device to secure the position of theelongated housing inside the lumen.
 43. The method of claim 37, furthercomprising measuring a temperature of the tissue while applying theradio frequency energy to the electrode.
 44. The method of claim 43,further comprising controlling the amount and the duration of the radiofrequency energy applied to the electrode in response to the measuredtemperature.
 45. The method of claim 37, further comprising deliveringfluid to the tissue through the elongated housing.
 46. The method of theclaim 39, wherein the needle electrode is hollow and further comprisingdelivering fluid to the tissue through the hollow electrode.
 47. Themethod of claim 37, further comprising measuring an impedance near adistal end of the electrode.
 48. The method of claim 37, furthercomprising: connecting the distal end of the elongated housing to anactuator in communication with a foot pedal; and stepping on the footpedal to deploy the electrode.
 49. The method of claim 48, furthercomprising stepping on the foot pedal to apply radio frequency energy tothe electrode.
 50. The method of claim 48, further comprising steppingon the foot pedal to deliver fluid through to the tissue through theelongated housing.
 51. The method of claim 48, further comprisingstepping on the foot pedal to activate a temperature sensor disposednear a distal end of the electrode.